The present invention relates generally to medical devices and in particular aspects to embolization devices.
As further background, during the diagnosis, treatment, and follow-up of various medical conditions, it may be necessary or desirable for a physician to occlude a passageway or other open space within a patient's body. For example, a physician may need to block a particular blood vessel, deprive a certain area of life-sustaining blood, or fill a cavernous area in a blood vessel. In situations where a blood vessel is perforated, blood can flow out of the vessel and into surrounding areas causing a hemorrhage. For this condition, the physician will need to, inter alia, plug the perforation and/or occlude the vessel upstream of the perforation. In another example, where a tumor is discovered, one therapy for reducing the tumor or eliminating it completely is to occlude the vessel upstream of the tumor. In some instances, the blood-deprived tumor will die off. In both of these examples, a strategically placed thrombus or embolism completes the desired occlusion.
In the case of aneurysm treatment, an aneurysm is caused by a weakening of the vessel wall, which causes an invagination of the vessel wall. Blood flow is inhibited at the neck of the aneurysm due to turbulence caused by blood entering and exiting the lumen of the aneurysm. An aneurysm in the brain, especially one that has ruptured, can have catastrophic consequences including but not limited to subarachnoid hemorrhage, stroke, permanent neurological deficits, and death.
Surgical procedures to treat aneurysms, e.g., aneurysm “clipping,” can be extremely risky, and in some cases, impossible depending on the anatomical location of the aneurysm. As an alternative to surgery, a number of minimally invasive procedures have been developed whereby both ruptured and unruptured aneurysms can be treated using embolization devices. Such devices can include aneurysm coils, injectable “fillers,” and various other implants. In some instances, one or more embolization devices are delivered to an aneurysm treatment site using a catheter (and possibly a guide-wire) that is advanced from the groin to the treatment site. An embolization device is then inserted through the catheter and into the aneurysm. Such a procedure can be repeated until enough devices are “packed” into the aneurysm sac to fill it.
A common treatment method for cerebral aneurysms involves the implantation of metallic embolization coils into the lumen of the aneurysm. One such coil is the FDA approved Gugliemi Detachable Coil. However, this platinum coil has limited thrombus promoting characteristics and typically does not provide a complete packing of the aneurysm lumen. It is not uncommon for an aneurysm treated with such a device to re-canalize, enlarge, and even rupture. Therefore, an aneurysm lumen filling device that suitably packs the lumen, is configured to reduce the chance of device migration following implantation, is biocompatible, and promotes healing of the aneurysm would be well-received as, by one estimate, approximately 28,000 patients suffer from intracranial aneurysms, of which 19,000 become severely disabled or die as a result of an aneurysm rupture.
There remain needs for improved and/or alternative embolization devices, as well as methods for manufacturing and using such devices. The present invention is addressed to those needs.